FIG. 1 shows an example of a traditional approach for carrying telephony traffic. Telephony traffic is traditionally carried over a telephony network 103. As is known in the art, a telephony network 103 employs: 1) circuit switching to set up a connection; and 2) time division multiplexing (TDM) to transport information over the connection. Some examples of a telephony network include a Public Switched Telephone Network (PSTN) or an Integrated Services Data Network (ISDN).
Telephony traffic is traffic traditionally carried by a telephony network such as voice traffic and facsimile (FAX) traffic. In the example of FIG. 1, telephony traffic is carried by the telephony network 103 from a source device 101 (e.g., a telephone mouthpiece or transmitting FAX modulator) to a destination device 102 (e.g., a telephone earpiece or receiving FAX demodulator).
Note that, as an example, both the source device 101 and the destination device 102 are coupled to a corresponding local exchange or end office 180, 181 (LE/EO). A local exchange typically handles traffic from a smaller geographic region while a central exchange typically handles traffic from a larger geographic region. Because either may apply to the exemplary depiction of FIG. 1, the notation LE/EO 180, 181 has been used.
The source device 101 is coupled to LE/EO 180 (which may also be referred to as the source LE/EO 180) and the destination device 102 is coupled to LE/EO 181 (which may also be referred to as the destination LE/EO 181). An LE/EO, such as source LE/EO 180, provides for the efficient collection of information from different source devices. That is, traffic entering the telephony network 103 (e.g., from a plurality of different telephone mouthpieces and/or transmitting FAX modulators) may be combined at a LE/EO 180 and transported further upstream (i.e., deeper into the telephony network 103) over a single trunk line 113 (e.g., a T1 line).
Similarly, a LE/EO such as destination LE/EO 181 also provides efficient distribution of information to different destination devices. That is, traffic leaving the telephony network 103 (e.g., toward a plurality of different telephone earpieces and/or receiving FAX demodulators) may be collectively received at a LE/EO from a single trunk line 118 (that is coupled to deeper regions of the telephony network 103) and then distributed from the LE/EO to the appropriate destination devices.
For any connection carried by the telephony network 103, the connection's establishment (e.g., call setup and teardown procedures) and routing path are controlled by a telephony signaling control network 104. An example of a telephony signaling control network 104 is a Signaling System 7 (SS7) network. SS7 networks, which include local and national variants, are implemented world-wide.
As an example, when an individual at the source device 101 attempts to call an individual at the destination device 102, the information indicative of the source and destination devices (e.g., an Initial Address Message (IAM) message) is typically forwarded from the source LE/EO 180 to a signaling transfer point (STP) 105 within the telephony signaling control network 104. The STP 105 (which may also be referred to as the “source” STP 105) helps arrange notification of the call to STP 106 (which may also be referred to as the “destination” STP 106) responsible for the destination LE/OE 181.
Upon such notification, the destination STP 106 will forward the IAM message to the destination LE/EO 181. The destination LE/OE will then notify the destination device 102 of the call (e.g., via a “RING” signal). The destination LE/EO 181 is also informed, from the telephony signaling control network 104, which TDM time slot on trunk line 118 that the information from the call is to be sent along. Generally, when multiple switches (i.e., more than two) are used to carry a call, a switch communicates the TDM time slot and trunk line (through the telephony signaling control network 104) to the next switch used to carry the call.
A problem with telephony networks is their inherent emphasis on the transportation of telephony traffic. With the growth of the Internet, service demand for the transportation of data traffic (e.g., traffic between computing devices such as e-mails, HTML files, etc. exchanged between computers) has sharply risen. Unfortunately, the TDM approach employed by a telephony network is a networking architecture that is particularly tailored for the carrying of voice conversations. As a result, a telephony network does not efficiently handle the transportation of both voice and data traffic.